Environment free switch



Dec. 26, 1961 O. S. GREESON 3,015,010 ENVIRONMENT FREE SWITCH Filed Nov.27, 1959 2 Sheets-Sheet 1 Orion 5. Greeson INVENTOR. BY yzwy 3m Dec. 26,1961 o. s. GREESON 3,015,010

ENVIRONMENT FREE- SWITCH Filed Nov. 27, 1959 2 Sheets-Sheet 2 as 62 95?90 I 88 54 a a2 60 42 Fig. 5

WW Em States This invention relates generally to switches and moreparticularly to a maintained-position switch which is hermeticallyseated within a housing so as to be absolutely isolated fromenvironmental eifects.

It is the principal object of this invention to provide a novel switchconstruction which is stable in either of two positions and which may beswitched from a first to a second position by merely depressing a switchactuator.

It is a further object of this invention to provide a novel switchingassembly which is hermetically sealed within a housing so as to enablethe switch assembly to be divorced from harmful environmental eifects.An elastic diaphragm is provided and comprises one wall of the housingenabling the switch actuator of the switch assembly to be depressedthrough the elastic diaphragm.

It is a still further object of this invention to provide a novel switchconstruction which is relatively simple and accordingly easy to operateand inexpensive to manufacture. Also, the simplicity of constructionassures reliable and long-lasting operation.

In order to isolate the switch assembly from the harmful environmentalelfects, the housing is hermetically sealed. The switch is therebysealed against explosive laden atmosphere or vapors and accordingly isexplosion proof. Further, the switch is sealed against water, oilcorrosive fumes, vapors, dirt, and other things that might causemalfunctioning and a shortened life. The housing is constructed of metalwhich is preferably electrically grounded so as to reduce the danger ofshock. All switch elements are constructed of metal except theinsulation which is of an inorganic material such as glass, ceramic, orthe like. Inorganic material is utilized inasmuch as it is Well-knownthat electrical contacts which are sealed within an atmosphere incohabitation with organic material, are subject to vary rapiddeterioration which would ultimately cause mal-functioning and shortlife. Inasmuch as the entire switch construction is of metal, glass,ceramic, or the like, the switch is substantially heat resistant andaccordingly it will withstand heat generated within the housing and alsohigh ambient temperatures. Also, the construction will allow hightemperature manufacturing techniques, such as soldering, brazing orwelding, to be employed. The design of the switch permits the ruggedconstruction which will withstand frequent operation without requiringmaintenance. It is contemplated that the switch may be utilized in anyof various devices for operation by hand, foot, elbow, etc., inasmuch asonly very short, momentary movements need be imparted thereto. Also, themovements may be imparted by various kinds of mechanical devices or byelectromagnetic devices.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view of the switch illustrating theexternal housing construction;

FIGURE 2 is a front end elevational view of the switch illustratingparticularly the elastic diaphragm;

FIGURE 3 is a rear end elevational view of the switch illustratingparticularly the terminal connections thereto;

FIGURE 4 is a vertical sectional view taken substantially along theplane 4-4 of FIGURE 2;

3,015,010 Patented Dec. 26, 1961 FEGURE 5 is an elevational plan view ofthe switch assembly supported within the housing;

FIGURE 6 is a vertical sectional view of the switch assembly takensubstantially along the plane 6-6 of FIG- URE 5; and

FIGURE 7 is a vertical sectional view taken substantially along theplane 7-7 of FIGURE 5.

With continuing reference to the drawings and initial reference toFIGURES 1 through 4, numeral 10 generally represents the environmentfree switch comprising this invention and including a cylindricalhousing 12 formed of metal and receiving a metallic end plate 14therein. The end plate 14 has a pair of cylindrical insulators l6 and 18extending therethrough and receiving conductors 2G and 22 respectivelyterminating in contacts 24 and 26. The contact 24 has a spring 28connected thereto and terminally carries a contact 30 in alignment withcontact 26.

An elastic diaphragm 32 is fitted over the end of the housing 12 remotefrom the end plate 14. The diaphragm 32 is made of thin, highly elasticmaterial such' as spring steel, spring brass, or the like and is formedinto a series of concentric corrugations 34. The particular corrugatedconstruction provides a rugged structure which will not be adverselyaffected by wear. weathering, aging or ordinary physical abuse. Also,sufiicient elasticity is provided to operate a switch actuator withinthe housing 12 in a manner to be more particularly described below. Aswitch assembly, generally designated by the numeral 36 is supported inthe housing 12 by a support 38 extending from the end plate 14. A rivet40 connects the base 42 of the switch assembly 36 to the support 38.

Attention is now drawn to FIGURES 5 through 7 wherein the details of theswitch assembly 36 are illustrated. The numeral 42 indicates the switchassembly base and includes a vertical leg 44 and a horizontal leg 46including a reduced portion 48. Extending through the vertical leg 44 isa rod 50 having a head 52. A spring 54 is received around the rod Stlbetween the head 52 and vertical leg 44. Secured to the rod 50 is adriving head 56. The driving head 56 includes a downturned leg 58 whichdefines an opening 61 therein for passing the reduced portion 48 of thebase horizontal leg 46. The driving head 56 is adapted to control theposition of a cradle 66 through a motion transmitting mechanism to befurther defined.

The cradle 60 is a U-shaped structure including leg portions 62 and 64and bight portion 66. The bight portion 66 has a reduced lower portion68 which defines an opening 70 therein through which the reduced portion48 of the horizontal base leg 46 passes. The leg portions 62 and 64 passthrough slots 72 and 74 in the vertical leg 44 of the base 42.Accordingly, the leg portion sliding in the vertical leg 44 and thebight portion sliding on the base 42 assures cradle movement in astraight line. The cradle 69 is urged toward a position proximate to thediaphragm 32 by the contact spring 28 which may be supplemented by anauxiliary spring. An insulator 76 is secured to the bight portion 66 ofthe cradle 60 and insulates the contact spring 28 from the cradle 60.

The motion transmitting mechanism heretofore mentioned includes adriving pawl 78 and a latching pawl 80. Each of the pawls 78 and 86 areL-shaped structures having vertical and horizontal legs. Springs 82 and84 are afiixed to the bight portion 66 of the cradle 60 by 'fastener 87and the springs 82 and 84 respectively ex- 78. The spring 90 urges thearm 88 upwardly with respect to the driving pawl 78 and the movement islimited by a trip pin 92 secured to the driving pawl 78 and extendingthrough an opening 94 carried on the lower edge of the arm 88. The arm88 has a guide pin 96 secured to the end thereof. The driving head 56has an upper surface 98 and a lower surface 1630 providing a step orabutment 102 therebetween. The free end of the driving pawl 78cooperates with the surfaces 98 and 100 and the step 102 in driving thecradle 60. An upturned leg 194 is formed over to provide a projection-of cross-section 1116. The projection 106 cooperates with the guide pin96 on the arm 88 in controlling the action of the motion transmittingmechanism.

The latching pawl 80 engages a stop surface 108 which is attached to thebase 42. The step surface 103 has an upper surface 110 and a lowersurface 112. The surfaces 110 and 112 define a step 114 therebetween,the cradle 60 is locked in its forward position with the conductors 20and 22 bridged when the latching pawl 80 is in engagement with the step114.

In the operation of the device, the diaphragm 34 is depressed to movethe switch actuator or rod 54). With the dimensions contemplated, it isonly necessary to depress the diaphragm approximately /8 of an inch. Itshall be assumed that in the initial position, the driving pawl 78 restson the lower surface 100 in engagement with the step 102 of the drivinghead 56. The latching pawl 80 rests on the upper surface 111) back ofthe step 114 of the step surface 108. FIGURES 5 through 7 illustrate theswitch assembly in the initial position. Both pawls are tensioned intheir respective positions by springs 82 and 84. The arm 88 is tensionedupward by spring 90 such that the bottom of the opening 94 bears againstthe trip pin 92. The guide pin 96 on the free end of arm 88 ispositioned in back of the inclined surface of the projection 106 of thedriving head 56. The driving head 56 is tensioned toward the rear by thespring 54 bearing against head 52. The cradle 60 is likewise tensionedto the rear by the spring 28 acting against the insulator 76. Therefore,conductors 20 and 22 will remain open.

It shall now be assumed that pressure is applied to the diaphragm 32moving the rod 50 and driving head 56 forwardly. The cradle 60 will alsobe driven forward by the driving pawl 78 bearing against the step 102 onthe driving head 56. Insulator 76 will be carried forwardly and bearingagainst the spring 28 so as to engage the contacts 30 and 26 to bridgethe conductors 20 and 22. Simultaneously, the latching pawl 80 travelsalong the upper surface 110 and drops to the lower surface 112 so as tobear against the step 1-14. The cradle 60 is then locked in its forwardposition thus maintaining the conductors 20 and 22 bridged.

When pressure on the diaphragm 32 is released, the driving head 56 isurged to its rearward position by spring 54. As the driving head 56moves rearwardly, the lower surface 100 of the driving head 56 movesrelative to the pawl 78. At the same time, the guide pin 96 is ridingalong the lower or rear of the inclined surface'106 of the projection106 and the free end of the arm 88 is forced downwardly against thetension of spring 91). When the pin 96 passes the projection 106, spring90 relaxes and the arm 88 springs up so that the pin 96 is thenpositioned forwardly of the projection 106. The switch assembly stillmaintains the conductors 20 and 22 bridged. When it is desired todisengage the contacts 26 and 30, pressure is again applied to thecorrugated diaphragm 32 and again the driving head 56 is movedforwardly. The guide pin 96 now rides up the forward or upper face ofthe projection 106 and the free end of the arm 88 is forced upwardly.The bottom of the opening 94 of the arm 88 acts against the trip pin 92so as to raise the driving pawl 78 and latching pawl 80, releasing thecradle 60 which is then urged to its rearward position by spring 28. Ofcourse, contacts 26 and 30 will become disengaged.

Then, when the pressure of the diaphragm 32 is released, the drivinghead 56 is urged to its rearward position by spring 54 and the switchassembly is again in position to be operated.

From the above, it will be appreciated that a novel switch constructionhas been disclosed wherein the elements of the switch assembly aresealed within a housing so as to divorce the working elements fromharmful environmental effect.

The foregoing is considered as illustrative only of the principies ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. An environment free switch comprising a sealed housing, a pair ofspaced terminals extending into said housing, an elastic diaphragmcomprising one wall of said housing, switch assembly means havingretracted and extended conditions and movably supported in said housingfor movement while in one of said conditions in response to displacingengagement of said diaphragm, and biasing contact means connected to oneof said spaced terminals within the housing and operative to make orbreak contact with the other of said terminals and change the conditionof said switch assembly means in response to engagement of saiddiaphragm.

2. The combination of claim 1 wherein said switch assembly meansincluding a switch actuator means disposed adjacent to said diaphragmfor manual depression thereof therethrough, and operatively connected tothe biasing means when the switch assembly means is in extendedcondition for making contact with the other terminal and operative whenthe switch assembly means is in retracted condition to release thebiasing means for breaking contact.

3. The combination of claim 2 wherein said switch assembly means furtherincludes means for holding the switch assembly means in either retractedor extended condition and thereby operatively connect said switchactuator means to said biasing contact means for selectively retainingsaid contact means in either an open contact or bridged closed contactposition.

4. The combination ofclaim 3 wherein said holding means including a basesupported in said housing, for slidably mounting the switch actuatormeans, and spring means supported between said base and said actuatormeans for urging said actuator toward said diaphragm.

5. An environment free switch comprising a sealed housing, a pair ofspaced terminals extending into said housing, an elastic diaphragmcomprising one wall of said housing, a switch assembly supported in saidhousing and actuatable through said diaphragm for bridging said spacedterminals, said switch assembly including a switch actuator disposedadjacent to said diaphragm whereby said actuator may be manuallydepressed through said diaphragm, a bridging element, means operativelyconnecting said switch actuator to said bridging element for selectivelyretaining said element in either an open or bridged position, said meansincluding a base supported in said housing, a cradle slidable upon saidbase, said cradle supporting a driving pawl and a latching pawl, adriving head, said driving head secured to said actuator and slidable onsaid base, said driving head aligned with said driving pawl wherebyslidable movement of said actuator may slidably drive said cradle.

6. An environment free switch comprising a sealed housing, a pair ofspaced terminals extending into said housing, an elastic diaphragmcomprising one wall of said housing, a switch assembly supported in saidhousing and actuatable through said diaphragm for bridging said spacedterminals, said switch assembly including a switch actuator disposedadjacent to said diaphragm whereby said actuator may be manuallydepressed through said diaphragm, a bridging element, means operativelyconnecting said switch actuator to said bridging element for selectivelyretaining said element in either an open or bridged position, said meansincluding a base supported in said housing, a cradle slidable upon saidbase, said cradle supporting a driving pawl and a latching pawl, adriving head, said driving head secured to said actuator and slidable onsaid base, said driving head aligned with said driving pawl wherebyslidable movement of said actuator may slidably drive said cradle,stepped surface secured to said base and aligned with said latching pawlwhereby said latching pawl may abut said stepped surface to preventslidable movement of said cradle.

7. An environ-ment free switch comprising a sealed housing, a pair ofspaced terminals extending into said housing, an elastic diaphragmcomprising one wall of said housing, a switch assembly supported in saidhousing and actuatable through said diaphragm for bridging said spacedterminals, said switch assembly including a switch actuator disposedadjacent to said diaphragm whereby said actuator may be manuallydepressed through said diaphragm, a bridging element, means operativelyconnecting said switch actuator tosaid bridging element for selectivelyretaining said element in either an open or bridged position, said meansincluding a base supported in said housing, a cradle slidable upon saidbase, said cradle supporting a driving pawl and a latching pawl, adriving head, said driving head secured to said actuator and slidable onsaid base, said driving head aligned with said driving pawl wherebyslidable movement of said actuator may slidably drive said cradle,stepped surface secured to said base and aligned with said latching pawlwhereby said latching pawl may abut said stepped surface to preventslidable movement of said cradle, an arm, each of said driving pawl,latching pawl and arm pivotally mounted on a common axis supported bysaid cradle, a pin secured to said driving pawl and receivable throughan opening in said arm, said driving pin abutting said latching pawl.

8. An environment free switch comprising a sealed housing, a pair ofspaced terminals extending into said housing, an elastic diaphragmcomprising one wall of said housing, a switch assembly supported in saidhousing and actuatable through said diaphragm for bridging said spacedterminals, said switch assembly including a switch actuator disposedadjacent to said diaphragm whereby said actuator may be manuallydepressed through said diaphragm, a bridging element, means operativelyconnecting said switch actuator to said bridging element for selectivelyretaining said element in either an open or bridged position, said meansincluding a base supported in said housing, a cradle slidable upon saidbase, said cradle supporting a driving pawl and a latching pawl, adriving head, said driving head secured to said actuator and slidable onsaid base, said driving head aligned with said driving pawl wherebyslidable movement of said actuator may slidably drive said cradle,stepped surface secured to said base and aligned with said latching pawlwhereby said latching pawl may abut said stepped surface to preventslidable movement of said cradle, an arm, each of said driving pawl,latching pawl and arm pivotally mounted on a common axis supported bysaid cradle, a pin secured to said driving pawl and receivable throughan opening in said arm, said pin abutting said latching pawl, springmeans supported between said housing and said pawls for respectivelyurging said driving pawl and said latching pawl into engagement withsaid driving head and said stepped surface.

9. An environment free switch comprising a sealed housing, a pair ofspaced terminals extending in'o said housing, an elastic diaphragmcomprising one wall of said housing, a switch assembly supported in saidhousing and actuatable through said diaphragm for bridging said spacedterminals, said switch assembly including a switch actuator disposedadjacent to said diaphragm whereby said actuator may be manuallydepressed through said diaphragm, a bridging element, means operativelyconnecting said switch actuator to said bridging element for selectivelyretaining said element in either an open or ridged position, said meansincluding a base supported in said housing, a cradle slidable upon saidbase, said cradle supporting a driving pawl and a latching pawl, adriving head, said driving head secured to said actuator and slidable onsaid base, said driving head aligned with said driving pawl wherebyslidable movement of said actuator may slidably drive said cradle,stepped surface secured to said base and aligned with said latching pawlwhereby said latching pawl may abut said stepped surface to preventslidable movement of said cradle, an arm, each of said driving pawl,latching pawl and arm pivotally mounted on a common axis supported bysaid cradle, a pin secured to said driving pawl and receivable throughan opening in said arm, said pin abutting said latching pawl, springmeans supported between said housing and said pawls for respectivelyurging said driving pawl and said latching pawl into engagement withsaid driving head and said stepped surface, an inclined surface, a guidepin carried by said arm, and a spring secured between said driving pawland said arm for urging said guide pin into engagement with saidinclined surface.

10. An environment free switch comprising a sealed housing, a pair ofspaced terminals extending into said housing, an elastic diaphragmcomprising one wall of said housing, a switch assembly supported in saidhousing and actuatable through said diaphragm for bridging said spacedterminals, said switch assembly including a switch actuator disposedadjacent to said diaphragm whereby said actuator may be manuallydepressed through said diaphragm, a bridging element, means operativelyconnecting said switch actuator to said bridging element for selectivelyretaining said element in either an open or bridged position, said meansincluding a base supported in said housing, said switch actuator mountedfor reciprocably slidable movement through said base, and spring meanssupported between said base and said actuator for urging said actuatortoward said diaphragm, a cradle slidable upon said base, said cradlesupporting a driving pawl and a latching pawl, a driving head, saiddriving head secured to said actuator and slidable on said base, saiddriving head aligned with said driving pawl whereby slidable movement ofsaid actuator may slidably drive said cradle.

11. An environment free switch comprising a sealed housing, a pair ofspaced terminals extending into said housing, an elastic diaphragmcomprising one wall of said housing, a switch assembly supported in saidhousing and actuatable through said diaphragm for bridging said spacedterminals, said switch assembly including a switch actuator disposedadjacent to said diaphragm whereby said actuator may be manuallydepressed through said diaphragm, a bridging element, means operativelyconnecting said switch actuator to said bridging element for selectivelyretaining said element in either an open or bridged position, said meansincluding a base supported in said housing, said switch actuator mountedfor reciprocably slidable movement through said base, and spring meanssupported between said base and said actuator for urging said actuatortoward said diaphragm, a cradle slidable upon said base, said cradlesupporting a driving pawl and a latching pawl, a driving head, saiddriving head secured to said actuator and slidable on said base, saiddriving head aligned with said driving pawl whereby slidable movement ofsaid actuator may slidably drive said cradle, said base including avertical leg and a horizontal leg, said horizontal leg defining areduced portion, said cradle being of a U-shape defining a bight portionand a pair of leg portions, said reduced portion of said horizontal legextending through said bight portion, said leg portions extendingthrough said vertical leg.

References Cited in the file, of this patent UNITED STATES PATENTSSchellman Oct. 12, 1948

